cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A347638 Number of minimal dominating sets in the n-dipyramidal graph (for n > 3).

Original entry on oeis.org

3, 7, 10, 15, 16, 18, 29, 31, 40, 48, 67, 82, 105, 143, 189, 255, 341, 474, 647, 892, 1236, 1719, 2393, 3330, 4656, 6503, 9094, 12719, 17807, 24931, 34907, 48895, 68490, 95951, 134420, 188338, 263885, 369743, 518080, 725940, 1017211, 1425346, 1997265, 2798671
Offset: 1

Views

Author

Eric W. Weisstein, Sep 09 2021

Keywords

Comments

The 3-dipyramidal graph deviates from this sequence because it has 4 minimal dominating sets while a(3) = 10.

Crossrefs

Cf. A253413.

Programs

  • Mathematica
    Table[2 n + 1 + RootSum[1 - #^2 - #^3 - #^4 + #^6 &, #^n &], {n, 20}]
    LinearRecurrence[{2, 0, -1, 0, -1, 0, 2, -1}, {3, 7, 10, 15, 16, 18, 29, 31}, 20]
    CoefficientList[Series[(3 + x - 4 x^2 - 2 x^3 - 7 x^4 - x^5 + 15 x^6 - 7 x^7)/((-1 + x)^2 (1 - x^2 - x^3 - x^4 + x^6)), {x, 0, 20}], x]

Formula

a(n) = A253413(n)+2*n+1.
a(n) = 2*a(n-1)-a(n-3)-a(n-5)+2*a(n-7)-a(n-8).
G.f.: x*(3+x-4*x^2-2*x^3-7*x^4-x^5+15*x^6-7*x^7)/((-1+x)^2*(1-x^2-x^3-x^4+x^6)).